Feed means for cleaning machines



Dec. 18, 1945. J. F. MALSBARY FEED MEANS FOR CLEANING MACHINES Filed NOV. 26, 1943 I HVVENTUR, JOB F. MALSBARY. BY f f ATT0RNK Patented Dec. 18, 1945 1 ITED" STAT-ES PATENT OFFICE v n v2,391,177 V r a t FEED, FOR CLEANING WW5- Job F. Malsbary, Oakland, Calif., 'assignor'to rMalsbary Manufacturing Company, Oakland,

'CaIiL, a. copartnersh'ip composed of Job F. Malsbary and Walter W. "Taylor Application :November 26, 1s4s,1sernlnu.511,soa

(crass-s37 11 Claims.

The present invention relates to improvements inxfeeding means for cleaningmachlnesadapted particularly rm- "cleaning trucks, tractors, automobiles and the like. I .Aacleariingmachine ofzthts types-is illustrated anddescribedin Patent No. 395,228, issued to myseltzandwalter W. Taylor-as co-inventorson September.'8th, 1942; a v

V In the patented machinelt was proposed to :feed aliquid solution to a pinnp'irom two different tanks, one containing-water and the other a cleaning :solution, to dischargefrom thepump intma: coil :for heating the resulting solution and to: discharge from the-coil I through a. hose and -.a nozzlehavmg a restricted-orifice.

it was--further proposed to utilize a pump of a papacity considerable in-excess @0! the normal requirements'wof the :coil, .to provide control meansfor producing-a wide variety of :sprays at the option of the operator, and'to movideiurther control means for by-passing the excess'siiquid discharged by the pump back .to-the :lntaikezside of the; pump tor: eltecting a more thorough mixingwoflthe ingredients.

. .Inthe patented machine the solution tank was placedat a. higher level than-thewater tank so as to feed the solution into the water-under a certainiamount of pressure, the pipeconnection from vithe iwaterttank to the pump -heing prosided with acheck-valve to present the solution .whole wassatisfactory, it wasfoundthat occasionally, due to a leaky check valve, the solution would flow into the water tank duringran extended period of "rest, as at night time, and'would flood. the water tank; the solution tank being much larger than the water tank.

vThe-water was red rrom the water'tankthrough a strainer, and .it was further found, that even a relatively, small amount 0! solution reaching the water tank accidentally would tend to clog .thestrainer. due to the reaction of the soapin the cleaning solution with the minerals-in the water precipitated on thestrainer. r In the present invention it is proposed to ameliorate this condition --generally by placing thesolution tank ata lower level-than the water tank soas to prevent any flow of the solution fromrthe solution tank to thewater tankunder theiorceof gravity. But .in this connection a different problemhad .to-;be met to prevent any V-part of the cleanin solution from reaching the; strainer the water tank Y heenpointed out, the pump has a capacity greatly in excess of the maximum coil, re-

:rquirements, the outlet side of the pump-usually registering a pressure voi about BOOpounds, while thekcoil pressure hardly ever exceeded a pres- ;smeoffitlll pounds imder'normal operating conditions. I

To accommodate the excess pressure and the excess volume Ied by: the pump the outlet conduit of the pump was provided with :a compression chamber anda relief valve connected to the pump intake Iorhy-passing any excess volume back to *sidexof :theplmip. arrangement satisfactory under normal operating condi- But it-would that with the pump in operation, feedtotheeoil or to the nozzle would bev shutofi. as by the operator laying aside the nozzle temporarily without stopping theppump, and iinvth'at case all-the, liquid pumped by the would he forced hack to the pump intake through :thereliet valve'and the by-pass. This wouldfurther tend to :increase theppressure in the pump outlet circuit, due to the resistance offered by the relief. valve and might :raise the pressure in the compression "chamber to 400 V This extreme pressure-would tendgto force'the liquid through-the relief valve in: surges-and, spasmodireally, at least; in quantities in excess of the capaxrity of the intake of the pump to absorb;

These spasmodic excesses would feed back'into the water through. a special relief passage (not-shown in-the patent) and both the solution and thewater'tank would begdrawn upon to compensate :for the amount of solution fed back to the water tank. I r

Thus thesolution would findits way intothe water tank with the result that the water in the tank would gradually'change into solution, with the deleterious reflect onthe strainer previously pointed It is the object of the present invention to overoomethis difliculty, principally, by providing a oompensating --device in the by-pass circuit In its general features my cleaning machine comprises a water tank I, a solution tank 2, a pump 3, a coil 4 provided with a heater 5, and a discharge hose 6 terminating in a'nozzle 1. i

The water tank may be of any suitable form' and is fed from the pipe 8,'a predetermined level being maintained by a float control 9. Water is fed from this tank through a strainer I0, the check valve II and the pipes I2, I3 and I4 to the intake side of the pump 3.

The check valve II is of the spring-loaded type and oifers a certain amount of resistance to water passing therethrough from the tank, for. purposes to be explained later. The combined length of the pipes I2 and I3 is considerable and adds to the resistance. The pipe I3 is preferably formed with a rubber joint I5 allowing of a .certain amount of expansion and contraction.

The solution tank is much larger than the water tank, and is fed from a water pipe IS, a float control I1 serving to shut off the supply when the water reaches a predetermined height. Any suitable soap or other cleaning medium may be dissolved in the water, and the pipe I6 may be closed by means of a valve I8. The outlet pipe I9 connects into the water pipes through a T 20. It is of much smaller diameter'than the water pipe and is provided with ashut-ofl valve 2I and a check valve 22.

The solution tank is disposed at a level lower than that of the water tank so that no solution will flow into the water tank under the force of gravity, even if the check valve I I shoulddevelop a leak.

The pump 3 is preferably of the double-acting type and comprises a housing 25 accommodating the pistons (not shown), an intake manifold-26 and exhaust manifold 21. The intake manifold connects with the pump chambers through intake valves 28 and receives liquid from the pipe I4. The exhaust manifold communicates'with the. pump chambers through delivery valves 29," and discharges, through pipes 30 and the valve'3I, into the coil 4. Th valve 3| maybe of any suitable type, preferably either a metering valve ora pressure-responsive reducing valve, depending upon general characteristics desired of the cleaning machine. '7 a The coil is mounted over a heater indicated at 5 and discharges through the hose 6 into the nozzle 1, which preferably has a restricted orifice. A handhold 32 may be provided for convenient handling of the hose and a valve 33 allows the coil outlet to be closed.

The pump is intended to have a capacity considerably in excess of the coil requirements. Under ordinary working conditions the pressure in the coil hardly ever exceeds 200 pounds while the pressure maintained in' the pump outlet circuit, up to the valve 3I, isco'nsiderably higher. This outlet circuit is provided with a compression chamber 34 to absorb surges and a relief or control valve 35 which may be set to maintain a pressure of 300 pounds in the outlet circuit, as

indicated on the gauge 36.

of expansion and contraction.

A suction "chamber or dome 40 is connected into the pipes 31-38. This chamber is preferably arranged fairly close to the intake side of the pump so that the suction of the pump becomes effective on the dome more immediately than on the two tanks Land 2, which are further away, particularly in view of the fact that the diameter of pipe 7 IELcoming from the solution tank, is very small,

and the pipe I2, coming from the water tank, is provided with the resistance of a spring-loaded check valve II.

Thus, in the normal operation of the machine, a large portion" of the liquid will be drawn out of thedome 40, leaving rarified air above the liquid.

In case pressures should develop which for some reason cannot be accommodated in the piping, th rubber couplings and the suction chamber 40, I provide an additional safety feature in the pipe 4| connecting the pipe I2 (underneath the check valve I I) with the water tank and discharging into the latter under water level, as at 42. A check 'valve'43' prevents return flow from the tank into the pipe.

The operation of the machine is as follows:

Normally th pump, drawing on the suction chamber 40 and on the two tanks creates a reduction of air pressure in the suction chamber and sucks in water from the tank I and solution from the tank 2, the solution mixing with the water atthe T' 20; The diluted solution enters the pumpintake and is forced through the discharge manifold into the outlet circuit.

Assuming that the relief valve 35 is set to respond to 300 pounds of pressure, the latter pressure will build up in the outlet circuit and will register on the gauge 36. The valve 3I may be set to discharge into the coil at a predetermined lower pressure, say 200 pounds, and the solution is finally discharged through the nozzle 1. Any excess amount of liquid pumped by the pump will be forced through the relief or control valve 35 and the pipes 31, 38 and I4, back into the intake side of the pump.

It, now, for some reason, the operator closes the valve or the valve 3|, no liquid can pass through the-outlet conduit, and all the liquid pumped has to'pass through the relief or control valve 35 to be by-passed back to the intake side of the pump. The relief valve and the conducting pipes will oppose resistance to the increased flow of liquid therethrough and will build up greater pressure in the outlet conduit 30,

which may register at the gauge 36 at say 400 pounds. a This increased pressure, in the attempt to force too much liquid through the pump will result in spasmodic surges, forcing spasmodically more liquid through the valve than the intake side of the pump can accommodate. v

In the absence of any provision for the contingency, and with an entirely rigid construction, the'system would begin to hammer, resulting eventually in breakage. With the suction chamber 40 omitted, but the by-pass II arranged as shown, the surges would cause excess amounts of liquid solution to be discharged into the water tank I, while during intermittent periods the "tion between-the source and the numpintake, a liquid xreceivingzelement, a connection between the pump outlet and the latter element having a compression chamber and relief valve therein,

would-be drawn 11mm to :a-considerable "extcnhpato compensate forz theramountw-of soluttonsdisohargcdinto the. tank; Thusthertank i troilldi:gradually :fill withsolution, with the detrimental result on the strainer 10 previously commented on..

The suction chamber M is intended to guard a ainst this. occurrence; Due to its proximity tolthe as compared to the relatively long distance to be travelled by the water from/the water tankand the-solution from the solution tank, and dust!) the further fact that the wa ter-iine-isprovided with the spring-loaded check walve'cr resistance. It, whilelthe solution-line is of relatively small diameter the :suction'chamber'will be drawn uponahead of' the two tanks and .will'ibe emptied sufficiently to accommodate the surges: caused by the high: pressure. The suction-chamber thuswservesaas a reserve chamber vadapted to accommodate surges and to release thesamein response tor-thesuction of the. pump.

,Since, in the operation of the pump, the. total output-corresponds to the total intake, and the surges are thus accounted for, there is no. casion for the surges to spread beyond the bypass circuit, and as a consequence no solution is pumped from the solution tank into the water tank.

While I have described the advantages of the suction chamber 40 principally in connection with the extreme case where all the output of the pump has to be by-passed back to the intake side of the pump, itis obvious that even in normal operation, the introduction of the suction chamber serves its purpose in smoothing out the operation and preventing pulsations in the line.

The rubber couplings l and 39 not only serve to facilitate assembling of the pipes but increase the flexibility of the system.

Thusmy new arrangement protects the, strainer [0 in two ways. The lower elevation of the solution tank prevents solution from flowing into the water tank by gravity; and the suction chamber 40 prevents solution by-passed by the pump from reaching the water tank.

I claim:

1. In a cleaning machine of the character described, a source of liquid, a pump, a connection between the source and the pump intake, a liquid-receiving element, a connection between the pump outlet and the latter element having a compression chamber and relief valve therein, a by-pass connection between the relief valve and the pump intake whereby excess liquid may be returned to the pump intake in a circulatory path, and a suction chamber in said by-pass connection for accommodating excessive surges in the latter.

2. In a cleaning machine of the character described, a source of liquid, a pump, a connection between the source and the pump intake, a liquid receiving element, a connection between the pump outlet and the latter element having a compression chamber and relief valve therein, a by-pass connection between the relief valve and the pump intake whereby excess liquid may be returned to the pump intake in a circulatory path, and a suction chamber in said by-pass connection for accommodating excessive surges in the latter, the connection from the source of liquid having a resistance therein for augmentating the suction effect of the pump on the suction chamber.

3. In a cleaning machine of the character described, a source of liquid, a pump, a connec- .a'Eby-pass connection between the relief valve and the pump intake whereby excesslliquid may belreturned to-the pump-intake in .a circulatory I path, and a ,suction chamber in said by-pass connection for accommodating the excessive surges in the latter, thev suction chamber being disposed in closer proximity to the pump than to the source of liquid so as to .be more immediately subtiect to the suction effect of the pump.

4. In a cleaning machine of the character dethe pump outlet and the. latter element having a compression chamber and relief valve therein,

a icy-pass connection between the relief valve and the. pump intake whereby excess liquid may bev returned to the pump intake in a circulatory path, and a suction chamber in said bY-pass connection for accommodating excessive surges in thelatter, the suction chamber being disposed in closer proximity to the pump than to the source of liquid so as to be more immediately subject to the suction effect of the pump, and the connection from the source of liquid having a resistance therein for augmentating the suction effect of the pump on the suction chamber.

5. In a cleaning machine of the character described, a tank for holding water, a pump, a connection between the tank and the pump intake including a strainer, a second tank for holding a cleaning solution, and a conduit leading from the second tank to the Water connection for feeding solution into the water, the second tank being disposed at an elevation lower than the strainer to prevent solution from flowing to the strainer under the force of gravity, the pump having means for discharging under high pressure and means for feeding excess liquid back to the pump intake, and the feed back having means for absorbing surges to prevent the latter from feeding back into the water tank.

6; In a cleaning machine of the character described, a tank for holding water, a pump, a connection between the tank and the pump intake including a strainer, a second tank for holding a cleaning solution, and a conduit leading from the second tank to the water connection for feeding solution into the water, the second tank being disposed at an elevation lower than the strainer to prevent solution from flowing to the strainer under the force of gravity, thev pump having means for discharging under high pressure and means for feeding excess liquid back to the pump intake, and the feed back having a suction chamber for absorbing surges to prevent the latter from feeding back into the water tank.

7. In a cleaning machine of the character described, a tank for holding water, a pump, a connection between the tank and the pump intake including a strainer, a second tank for holding a cleaningsolution, and a conduit leading from the second tank to the water connection for feeding solution into the water, the second tank being disposed at an elevation lower than the strainer to prevent solution from flowing to the strainer under the force of gravity, the pump having means for discharging under high pressure and means for feeding excess liquid back to the pump intake, the feed back having a suction chamber for absorbing surges to prevent the latter from feeding back into the water tank, and the water connection having a flow-resisting means to encourage suction of the pump intake on the suction chamber.

8. In a cleaning machine of the character described, a source of liquid, a pump, and a connection between the source and the pump intake, the pump having means for discharging under high pressure and means for feeding excess liquid back to the pump intake, and the feed back having means for absorbing surges to prevent the latter from feeding back into the source of liquid. 7

9. In a cleaning machine of the character described, a source of liquid, a pump, and a connection between th source and the pump intake, the pump having means for discharging under high pressure and means for feeding excess liquid back to the pump intake, and the feed back having a suction chamber for absorbing surges to prevent the latter from feeding back into the water tank.

10. In a cleaning machine of the character described, a source of liquid, a pump, and a connection between the source and the pump intake, the pump having means for discharging under high pressure and means for feeding excess liquid back to the pump intake, the feed back having a suction chamber for absorbing surges to prevent the latter from feeding back into the water tank, and the connection from the source having a flow-resisting means to encourage suction of the pump intake on the suction chamber.

11. In a cleaning machine of the character described; a source of liquid, a pump, a connection between the source and the pump intake, a

liquid receiving element, a connection between the pump outlet and the latter element having a compression chamber and a relief valve there-'- in, a by-pass connection between the relief valve and the pump intake whereby excess liquid may be returned to the pump intake in a circulatory path, and a suction chamber in said by-pass connection for accommodating excessive surges in the latter, the suction chamber having separate connections with the relief valve and the pump intake to insure uni-directional flow in said connection.

JOB F. MALSBARY. 

